From patchwork Sat Sep 30 02:53:12 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sergey Senozhatsky X-Patchwork-Id: 820162 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [103.22.144.68]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3y3tMv67fvz9s7f for ; Sat, 30 Sep 2017 12:55:39 +1000 (AEST) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="GUdbfzfI"; dkim-atps=neutral Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 3y3tMv4vKpzDqXv for ; Sat, 30 Sep 2017 12:55:39 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="GUdbfzfI"; dkim-atps=neutral X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=gmail.com (client-ip=2607:f8b0:400e:c00::244; helo=mail-pf0-x244.google.com; envelope-from=sergey.senozhatsky@gmail.com; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="GUdbfzfI"; dkim-atps=neutral Received: from mail-pf0-x244.google.com (mail-pf0-x244.google.com [IPv6:2607:f8b0:400e:c00::244]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3y3tKn4cpfzDqT0 for ; Sat, 30 Sep 2017 12:53:49 +1000 (AEST) Received: by mail-pf0-x244.google.com with SMTP id e69so844256pfg.4 for ; Fri, 29 Sep 2017 19:53:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=zj3SlvxnLTdIWARY0um/M6Dkxf+QLSrwBWG0N47LBdA=; b=GUdbfzfI/hLBwmcW4tYFRY9ej57Tb8o6ezH/3lZ1kiwN1VMdyNZQEZfKeXQ1rOKOb0 J3+9RACevBzyHW8z81SaUs2ohRxYZLfkhNVkiH9vi0D8H95IfzH2uKineHNj0yih9GOi hU4LWwneGuCQ0vRjrmatAlBVfeDAswcDTDOdLwO9b2kwBkB1BBMrFRkHaLgxFZz18yd7 fURJfSZ/Gl/Knx/WClFFIkQvHJNh9bMvnp5LhMeyMhwgxRyiFG9xkLux6A4+hJkwvOya WTtrsOGULVfFIHJp212SNtF4/7CtkTFOqT83B2bisDRfMCRuRE7+uT5RepIq4HjePiT7 2GoA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=zj3SlvxnLTdIWARY0um/M6Dkxf+QLSrwBWG0N47LBdA=; b=eN976ktzLt2kHhEwgz7h6MufRL2k3gHoZBs9JUn/ApYTn4abHcEbPwCiRngA7HDzOi nc/H69sD3XJFiAJUOWYHEAqBvArYAiMoEREOGaqRjQdArCiRho8PuYA1kafD+IANKomy wsokahjuGGNCioo+dSP5pmkcQ/rCL/8QwgmHAFbTmE18bb64cwfa5TPY/UVhAUciEiMo OD4V1cYPT7Q3P/XfhOegFyoO+bBqhZtZHNeVRV5lbFyyC2xafiA0ZcGNQLv9CEi2ImGK bc2aXBTKlRvjUPujcTEqHlN/JP6G/vAf0FlL3PNvgVVBRojcn1cbpA11m8HKjc9lopnU daiQ== X-Gm-Message-State: AHPjjUg/v873DdzqvtapMZgMLVl71g1TvLkI4CuZgUIv2NgJOJeVh7q7 0ktDt6Hr08eQ7RHHlQmxqs0= X-Google-Smtp-Source: AOwi7QDABB626ky+1qCqialxlEMALVLXlxFYFNHzlOxNwhdxJKQhoUnF7daKw78vSA1dS1V8Ar3fqQ== X-Received: by 10.99.49.205 with SMTP id x196mr4138185pgx.35.1506740025549; Fri, 29 Sep 2017 19:53:45 -0700 (PDT) Received: from localhost.localdomain ([175.223.27.84]) by smtp.gmail.com with ESMTPSA id b1sm8680714pgn.94.2017.09.29.19.53.37 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 29 Sep 2017 19:53:44 -0700 (PDT) From: Sergey Senozhatsky To: Petr Mladek , Steven Rostedt Subject: [PATCHv3 0/7] printk/ia64/ppc64/parisc64: let's deprecate %pF/%pf printk specifiers Date: Sat, 30 Sep 2017 11:53:12 +0900 Message-Id: <20170930025319.987-1-sergey.senozhatsky@gmail.com> X-Mailer: git-send-email 2.14.2 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.24 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Fenghua Yu , Tony Luck , linux-ia64@vger.kernel.org, linux-parisc@vger.kernel.org, Helge Deller , Jessica Yu , James Bottomley , Alexei Starovoitov , Sergey Senozhatsky , Paul Mackerras , Andrew Morton , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" Hello Petr, could you please pick up the series? ========================================================================== On some arches C function pointers are indirect and point to a function descriptor, which contains the actual pointer to the code. This mostly doesn't matter, except for cases when people want to print out function pointers in symbolic format, because the usual '%pS/%ps' does not work on those arches as expected. That's the reason why we have '%pF/%pf', but since it's here because of a subtle ABI detail specific to some arches (ppc64/ia64/parisc64) it's easy to misuse '%pF/%pf' and '%pS/%ps' (see [1], for example). This patch set attempts to move ia64/ppc64/parisc64 C function pointer ABI details out of printk() to arch code. Function dereference code now checks if a pointer belongs to a .opd ELF section and dereferences that pointer only if it does. The kernel and modules have their own .opd sections that's why I use two different ARCH functions: for kernel and for module pointer dereference. I planned to remove dereference_function_descriptor() entirely, but then I discovered a bunch other uses cases (kgdbts, init/main.c, extable, etc.), so I decided to keep dereference_function_descriptor() around because the main point of this patch set is to deprecate %pF/%pf. But at the same time, I think I can go further and handle both kernel and module descriptor dereference in dereference_function_descriptor(). We need a module pointer for module .opd check, so that will come at an extra cost of module lookup (may be there will some other issues along the way, haven't checked it). Right now we've got: - dereference_function_descriptor(addr) a generic (old) function. it simply attempts to dereference whatever pointer we give it. - dereference_kernel_function_descriptor(addr) dereferences a kernel pointer if it's within the kernel's .opd section. - dereference_module_function_descriptor(module, addr) dereference a module pointer if it's within the module's .opd section. v3: -- picked up ACKs and Tested-by -- tweaked checkpatch warning (Joe) -- updated Documentation v2: -- convert dereference_function_descriptor() to unsigned long -- fix kernel descriptor range checks (Helge) -- fix parisc module descriptor range check (Helge) -- fix ppc64 module range check -- add checkpatch patch Sergey Senozhatsky (7): switch dereference_function_descriptor() to `unsigned long' sections: split dereference_function_descriptor() ia64: Add .opd based function descriptor dereference powerpc64: Add .opd based function descriptor dereference parisc64: Add .opd based function descriptor dereference symbol lookup: use new kernel and module dereference functions checkpatch: add pF/pf deprecation warning Documentation/printk-formats.txt | 20 ++++++++++---------- arch/ia64/include/asm/sections.h | 16 ++++++++++++---- arch/ia64/kernel/module.c | 13 +++++++++++++ arch/ia64/kernel/vmlinux.lds.S | 2 ++ arch/parisc/boot/compressed/vmlinux.lds.S | 2 ++ arch/parisc/include/asm/sections.h | 4 +++- arch/parisc/kernel/module.c | 17 +++++++++++++++++ arch/parisc/kernel/process.c | 15 ++++++++++++--- arch/parisc/kernel/vmlinux.lds.S | 2 ++ arch/parisc/mm/init.c | 4 ++-- arch/powerpc/include/asm/module.h | 3 +++ arch/powerpc/include/asm/sections.h | 17 ++++++++++++++--- arch/powerpc/kernel/module_64.c | 16 ++++++++++++++++ arch/powerpc/kernel/vmlinux.lds.S | 2 ++ drivers/misc/kgdbts.c | 2 +- include/asm-generic/sections.h | 8 ++++++-- include/linux/moduleloader.h | 4 ++++ init/main.c | 2 +- kernel/extable.c | 2 +- kernel/kallsyms.c | 1 + kernel/module.c | 9 ++++++++- lib/vsprintf.c | 5 +---- scripts/checkpatch.pl | 11 +++++++++-- 23 files changed, 142 insertions(+), 35 deletions(-)